I have a new build of Ubuntu 18.04.1 LTS on a dedicated system, wiped and re-installed according to the WiKi on how to do it the easy way, a concise but invaluable bit of reference, many thanks for that.
For my own peace of mind the cameras are all on an isolated network with no internet access, they will be available to Zone minder through a second network card but will not be able to directly reach the internet.

After spending a few hours sifting through here and Amazon I thought I had just the Camera hardware I wanted, it even shows up if you search Amazon for Zoneminder poe
However I may have bought something else instead.

The cameras I have are H.View HV-400G2 and HV-400E1 POE and I'm fairly happy they are working as I can stream images using VLC from them.

If the cameras are onvif capable, I'd put them on your main network "temporarily" to be discovered by ZM's ONVIF discovery. Then just change the ip address when you move them back to your camera network.